Wallpaper trimmer&#39;s straightedge



April 1941- F. E. EDGREN 2,238,557

WALLPAPER TRIMMERS STRAIGHTEDGE Filed Oct. 24, 1938 Patented Apr. 15, 1941 UNITED STATES PATENT OFFICE 2,238,557 WALLPAPER TRIMMERS STRAI HTEDGE Fred E. Edgren, Chicago, 111. Application October 24, 1938, Serial No. 236,804 2 Claims. ,(01. 164-73) My invention relates to straightedges, used by wallpaper hangers in trimming'wallpaper, preferably made of comparatively light extruded metal possessing required strength and rigidity to enable a true and proper trimming of the wallpaper by such as an aluminum alloy, which-isunaffected by" T climatic conditions and which maybe readily applied to the main or body portion of the straightedge whether the latter be made of metal, wood, fibrous or other suitable material.

The invention has for its object the provision of a straightedge of any desired length composed of two units namely a body member and a track unit or guide member, immovablyand firmly secured together to provide therequisite dimensions necessary to permit use of the standard sized trimmers at present inuse and at the same time permit the guide member or track unit to be readily removed and replacedby theuser.

Another object of the invention is .the provision of straightedges wherein the track unit will be firmly held in proper engagement with the body member in such manner that a true and unobstructed vertical face on the track unit is provided for the circular rotating blade of the cutter device.

The above enumerated objects and the advantages of the invention will all bemore readily comprehended from the detailed description of the accompanying drawing, wherein- Figure 1 is a perspective view of a. portion of a straightedge involving'an embodiment of my invention. V

Figure 2 is a similar view of a portion of straightedge illustrating a modification.

Figure 3 is a perspective view of the lower. side of a portion of straightedge showing another modification.

Figure 4 is a view similar to Figures 1 and 2, showing another embodimentuof the invention.

Figure 5 is a perspective view asseen from the lower side and illustratinganother modification.

The invention contemplates a straightedge composed of two members orunits, each of which is composed of a single piece of rigid, non-warping material, preferablyextrudedim'etal, and provided with interengaging surfaces whereby the proper positioning and relation'of the units with each other will be provided: the two'units'in turn being removably securedltogether by readily 1removablemeans to.permit :easyiireplacement.

In the embodiment illustrated in Figure 1, the main body portion or unit is shown as a onepiece member of extruded metal, although it will be understood that this member may be made of wood or fibrous or moulded plastic material; the member being of any desired length and of comparatively narrow dimensions as is usual in a straightedge of the character in question. The body unit I, along one longitudinal edge, is shown provided with a flange H- which extends throughout the length of the body, with the lower longitudinal edge of the flange formed to provide a proper bearing surface on the paper to be trimmed andprovide av continuous true contact with the paper, while at the same time permitting the main body to be made comparatively thin to reduce weight and expense. l

The oppositelongitudinal ,side of the body I0 is offset vertically to form the laterally extending ledge l2, disposed beneath the plane of the main portion of the body. This ledge is of greater thickness than the main body in order to afford sufiicient strength for attachment of the guide unit l3 and also present a wide bearing surface disposed in the horizontal plane of the lower edge of the fiange ll.

The guide unit 13 consists of a single piece of extruded metal of somewhat channel form and of transverse dimensionsgreater than the thickness of ledge t2; the channeled side of the guide unit l3 being adapted to receive the ledge l2 of the body unit, withthe upper longitudinal side at its inner longitudinal edge reduced in thickness as shownat ,I 4 so as to be disposed in vertical spaced .=relation with the top surface of the ledge l2. The transverse width of theledge I2 is greater than the depth of the channelin the guide unit l3 with l the :resultthat the longitudinal edge I4 of the guide unit 'Wi11 be spaced from the longitudinal edge 15 ofthe body. unit.

The ledge I! of the body unit, on its upper surface, isiprovided with ,a longitudinally extending groove adapted to receive the longitudinally extending rib 16 formed on theinner surface of the upper sidewall of the guide unit l3, thereby providing an interlocking engagement between the two units; while the lower surface of the ledge I2 is chamfered to-receive the lower longitudinal side I! of the guide member l3 and permit the side I! to be.-flush with the bottom face of the ledge and in conjunctionwith the ledge provide a wide bearing surface for firmly holding the paper in place.

A asthefitraightedge is intended ,foruse with the "well known types of trimmers employing 194 outlation, however, being such that the guide unit l3 may be removed by sliding it lengthwise of the body and thus enable its easy removal when occasion requires. In order to prevent accidental lengthwise shifting of the guide unit, one or both ends of the guide unit on the bottom may be held in place by a suitable screw as shown at l9.

In Figure 2, the main body unit 20 has a similar flange I I, while the other longitudinal edge is provided with a ledge 2| which is substantially similar to ledge [2 of the embodiment shown in Figure 1, off-set vertically below the top of the main body portion, and adapted to receive the channel-like guide unit 23. The structure shown in Figure 2 differs from that of Figure l, in that the interlocking portions are arranged on the lower side of the ledge; the lower outer edge being chamfered and grooved to receive the bottom leg or side '24 and the upwardly disposed rib 25 formed on the longitudinal edge of the lower side 24.

A portion of the upper side of the guide unit bears on the upper face of the ledge 2|, while the longitudinal edge is reduced in thickness so as to be spaced above the ledge to provide a guideway for the trimming tool or cutter.

The sides of the groove in the ledge and the rib 25 are'preferably beveled as shown in order to more firmly draw the guideunit toward the body unit; and in order to prevent accidental longitudinal shifting of one unit on the other, the opposite ends of the guide unit may each be provided with a screw as at l9.

The construction shown in Figure 3 comprises a body unit 26, which may be made of extruded metal or wood and formed substantially similar to the body units II] and 20, except that the ledge 21 and the track unit 28 are not provided with interlocking portions; the channel-like track unit being adapted to receive the ledge 21 with its lower side chamfered to receive the lower leg or side 29 and permit it to extend flush with the bottom of the thickened ledge 21. The upper leg or side of the track unit bears on the top of the ledge, except at the longitudinal edge of unit 28, where the unit is reduced in thickness so as to be in vertical spaced relation with the top of the ledge to form a guide-way for the guide portion of the trimmer or cutting tool. As the two units in Figure 3 have no interlocking portions, the guide unit 28 is shown provided with a plurality of screws 30 extending through the lower leg or side '29 and into the ledge 21 and spaced apart longitudinally of the straightedge to maintain the guide unit in place.

In Figure 4 the body unit 3| has a vertically off- :set ledge 32 which is provided at its longitudinal edge and upper side with an upstanding rib or flange 33; while the lower side of the ledge 32 has a chamfer which terminates in a groove at 34.

The track unit 35 is substantially similar to track unit 23 in Figure 2, except that the upper leg or side 36 is provided with a groove adapted to receive the rib or flange 33 of ledge 32 of the body'unit; the outer longitudinal edge of the top side 36 being reduced in thickness so as to be vertically spaced above the ledge to provide a guide slot therebetween for the guide element on the paper trimmer orcutte'r and the lower leg or side of the track unit is provided with an upstand ing flange or portion 31 which enters the groove 34 in the bottom of the ledge.

This construction, in addition to the interen gaging relation, provides two interlocking portions which hold the two units together and hence any suitable means, as for example a small screw at. one or both ends of the straightedge, may be employed for preventing accidental longitudinal movement of one unit on the other.

In view of the interengaging relation between the two units in the constructions shown in Figures 1, 2, 3 and 4, the ledges are madecomparatively heavy to provide ample strength and purchase for the interlocking portions and the screws. It will be understood, that in the constructions shown in Figure 1, 2, and 4, the track units are 'slid endwisely onto the body units; while in the structure shown in Figure 3 the track unit may be edgewisely applied; the ledges and the track units in all instances combinedly providing comparatively wide pressure resisting and paper engaging, surfaces.

In the construction shown in Figure 5, the rear longitudinal edge of the body unit 38 is provided with a similar depending flange I I, while the, forward longitudinal edge is formed with a downwardly and outwardly sloping portion 39 which terminates at the bottom in a horizontally extending part 40. The forward side of the portion 39 adjacent the top surface of the body unit, for a short distance, preferably extends vertically at right angles to the top, as shown at 4|, and then slopes outwardly throughout the major part of portion 39. The downwardly and outwardly sloping face is provided with a longitudinal groove preferably extending from end to end of the mainrunit as shown at 42; the groove 42 being intended to receive a longitudinal tongue or rib 43 formed on the inner side of the track unit 44; the inner side of the track unit being beveled to correspond with the sloping surface of the body unit. The track unit 44 is provided with a flat surface disposed flush with the bottom surface 40 of the; bodyunit, with the forward vertical side arranged at right angles to the bottom and the top :to permit a trimming tool or circular knife to travel therealong. The top of the track unit 44 has an undercut groove 45 which provides a horizontally disposed flange 46 which terminates short of the inner face of the track unit and hence a distance removed from the forward surface of the bodyunit to permit insertion of the usual guide member of the paper trimmers; the guide member being adapted to slide along the groove 45 beneath the lip or flange 46.

In the construction of the device shown in Figure 5, relative movement, in a vertical direction, between the body unit and the track unit is prevented by the interengagement, but in or- ,der to prevent lateral displacement a series of screws 4'l-or other suitable fastening meansare preferably inserted from the underside of the cutter'engaging surface of the track unit.

. of the straightedge.

', tively 'soft brasslwhich constituted the track memberwa's readily indented by improper contact or blows, or marred by the cutting tool necessitating the discarding of the straightedge. In an effort to overcome these defects, straightedges have also been made of sheet metal bent and formed into proper shape to provide sufficient rigidity and strength and a separate sheet metal guide member was riveted or otherwise secured to the body member. Straightedges of this character are not only difiicult to manufacture accurately but also involve considerable expense in manufacture. In order to overcome these difficulties, a single piece straightedge having an integral guide and formed of extruded metal possessing sufficient rigidity and lightness, has been contemplated. Straightedges made of extruded metal, such as Duralumin, are more or less soft and consequently are easily cut into or indented along the paper contacting edge by the cutting tool and accurate trimming made difiicult; the straightedge no longer presenting a true smooth contacting surface with the paper at the point of knife contact.

The lower forward edge of the. straightedge must provide a sharp ninety degree angle for paper contact and as the vertical dimensions of the forward edge of the straightedge and the width of the guide flange must be maintained at definite measurements to receive and properly function with present day'wallpaper trimmers,

which are all made to standard measurements to maintain the trimmer or knife snugly against the straightedge. In view of this condition, it is apparent that a single piece straightedge with an integral track, all made of extruded metal,

could not be machined to eliminate the defects or inaccuracies, as such machining would decrease the required dimensions, with the result that the straightedge, although costly in manufacture, must be discarded.

My invention contemplates a straightedgewether the body portion be of extruded metal, or wood, or other suitable materialwith a track or guide unit which may be of extruded metal and which may be readily removed and replaced without necessitating the renewal of the entire straightedge; namely a straightedge whose body portion and track or guide portion are formed to have interengaging relation with each other to permit proper pressure to be placed thereon without permitting vertical displacement of the track unit and which will present a proper edge for firmly holding the paper to be trimmed in place.

The exemplifications shown in the drawing are believed to be the best embodiments of the invention, but certain modifications may be possible without, however, departing from the spirit of my invention as defined in the appended claims.

What I claim is:

1. A wallpaper trimmers straightedge comprising a body unit; a track or guide unit, the opposing sides of the two units having interlocking matching surfaces whereby relative lateral movement between the two units is prevented; and means whereby the two units are removably secured together against movement lengthwise of each other.

2. A wallpaper trimmers straightedge comprising a single piece main body unit formed with a plane upper surface and at its forward longitudinal side and beneath the top surface is provided with a laterally disposed extension having a flat bottom bearing surface, while the rear longitudinal side of the body unit is provided with a downwardly disposed flange extending into the horizontal plane of the bottom surface of said body extension; and a track or guide unit channeled on its inner vertical face to receive said extension, the bottom of said extension being chamfered to receive the lower side of the track unit to permit it to extend flush with the bottom of the extension and provide a wide fiat bearing surface, said extension and the track unit having interlocking matching surfaces whereby lateral movement between the two units is prevented, the top of the track unit being provided with a horizontal flange arranged inv the plane of the upper surface of the body unit and disposed toward the main body unit in spaced relation therewith and above said extension to provide a guide-way.

FRED E. EDGREN. 

